A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. including part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Conventional lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
Commonly, a lithographic apparatus includes a movable object. Such an object is movable with respect to another object, such as a frame, for instance a base frame or a metrology frame. An example of a movable object is a support structure of for instance the substrate or the patterning device, which may be movable to position the substrate and/or patterning device with respect to a radiation beam in a pattern transfer process, wherein a pattern is transferred from the patterning device to the substrate. Especially in scanners, both support structures are movable.
When an object is movable with respect to another object, cables and/or hoses may be provided between them to transfer power, data, fluids, etc. from one object to the other and vice versa. The movable object may include heat sources in the form of actuators which may position the movable object with respect to another object, or other heat sources. These heat sources may influence the temperature and/or temperature distribution of the movable object. When the movable object is used in the pattern transfer process of a lithographic apparatus the temperature is preferably controlled (possibly in the millikelvin range) in order to minimize imaging problems and/or overlay errors. In that case, the movable object may be temperature controlled by passing a fluid with a predetermined temperature through the movable object, wherein the fluid is transported in hoses to and from the movable object.
However, positioning cables and/or hoses between two relatively moving objects may limit the achievable position accuracy of the movable object(s), because the cables and/or hoses introduce force disturbances. In case of a fluid carrying hose, these force disturbances may be the result of inertia forces of the moving fluid itself and/or the interaction between the fluid and the acceleration or deceleration of the movable object. In combination with the tendency to decrease the mass of the movable objects and the increased demands with respect to accuracy and acceleration (>15 G), these disturbances become unacceptable and may result in imaging problems and/or overlay errors of the lithographic apparatus.